DevTools

DevTools is a client-side Fabric mod for Minecraft 1.14.4 through 26.3 that adds a powerful Inspect mode to your game. By freezing your movement and unlocking your cursor, you can point at blocks, fluids, dropped items, and entities to read rich, debug-style data directly on your screen.

It features customizable layouts, deep NBT-style data dumps, a registry browser (blocks, biomes, structures and entities), side-by-side Compare mode, biome coverage estimates, and clipboard copying.

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Requirements & Versioning

Requirement	Version / Constraint	Notes
Minecraft	1.14.4 – 26.3	Available for 1.14.4, 1.15.2, 1.16.5, 1.17.1/1.18.x, 1.19.4, 1.20.4, 1.21.5, 26.1, 26.2 and 26.3.
Mod Loader	Fabric Loader >=0.14.21	Newer minimums apply on newer versions (1.20: 0.15.11, 1.21: 0.19.2, 26.1: 0.18.6, 26.2: 0.19.3, 26.3: 0.20.1). Client-side only. Safe to leave in your mods folder when joining servers.
Fabric API	Required — match your game version	The mod uses the keybinding, lifecycle, networking and rendering modules, so it will not load without Fabric API.
Release	1.0.1.4	Same release for every supported Minecraft version.
Quilt	QFAPI	Supported on Quilt Loader in the 1.18.2 – 1.20.1 range.

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Quick Start

1. Install Fabric, then drop DevTools and the matching Fabric API into your mods folder.
2. Launch the game and enter a world.
3. Press F6 (default) to toggle Inspect mode.
4. Move your mouse over blocks or creatures, and Left-Click to select them.
5. Press M to expand detailed data for your selected target, or click the ↗ Expand bar at the bottom of the HUD.
6. Type into the Search field to browse blocks, biomes, structures and entities.
7. Head to Options -> DevTools… to tweak colours, toggle data lines, or change the layout.

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How Inspect Mode Works

When you turn Inspect mode on, the game adjusts your interactions so you can focus on the environment data.

Feature	Behaviour
Movement	You stay completely still. Movement is suppressed so you do not accidentally walk away from your inspection point.
Mouse Freedom	Your cursor is unlocked. Vanilla left-click does not punch blocks or attack; it is used exclusively for selecting targets.
Smart Raycasting	The mod picks targets based on camera + cursor. You can target blocks, flowing fluids, item entities on the ground, XP orbs, and mobs.
World Outlines	A thin outline shows what you are hovering over. A thicker, brighter outline shows what you have selected.
Scrolling	Use your mouse wheel over the info panel, search results, detail window or compare list to scroll through long text.
Registry Search	Search blocks, biomes, structures and entities at once; results are grouped by category and open in the detail window.
Detail Window	The ↗ Expand window button opens a large window with the complete dump and its own attribute filter.
Compare Mode	With a target selected, press Ctrl+C to open a comparison browser and pick a second block to compare against.

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Keybinds

All keys can be remapped under Controls -> DevTools. The info panel always displays the actual names of the keys you have currently bound.

Action	Default Key	Description
Toggle Inspect	F6	Turns Inspect mode on and off.
Select Target	Left Mouse	Locks the HUD onto the hovered block/entity. Click the same target again to deselect.
More Info	M	Toggles the detailed NBT/data dump.
Free Player	Hold L-Alt	Restores movement and camera while keeping Inspect on.
Copy Value	Ctrl + Click	Click any line in the HUD to copy its value to your clipboard.
Copy Popup	Ctrl + Shift + Click	Opens a cursor popup with Copy Key, Copy Value and Copy Line.
Compare Mode	Ctrl + C	With a selection, opens the compare browser.

Free Camera (Alt Mode)

If you hold Left Alt, you temporarily get your movement and camera controls back. Raycast updates are frozen, so the outlines stay fixed to your last targets, and the HUD becomes transparent so you can see the world.

Menu Suspensions

Opening any fullscreen menu (for example the Pause or Inventory screen) suspends and freezes raycasting and its updates, so you won't mess up your selection.

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The Info Panel (HUD)

The HUD is designed to provide immediate summary data, with the option to expand into detailed categories.

• Header: Shows if you are HOVERING or have a target SELECTED. Includes the icon of the selected block/entity, display name, and registry ID. Rarity colours automatically match vanilla Minecraft tiers (common, uncommon, rare, epic).
• Summary: Quick facts like coordinates, HP for living entities, or drop info for items.
• Search: Filters the visible lines/targets without leaving the world.
• Expand window Button: The ↗ Expand window button at the bottom opens the full-screen detail window for the selected (or hovered) target.
• Detailed Info ("More Info"): Hitting M opens a categorized text dump. Default category order: Source, Item Form, State Properties, Block Data, BlockEntity, Environment, Type, Identity, State, Living, Equipment, Effects, Mob, Raw NBT.
• Biome coverage: Biome details include an Estimated coverage line (see below).
• Boolean Styling: true / false lines are coloured distinctly for quick scanning.
• Copy Feedback: Successfully copying a line flashes a quick "copied" message.

Registry Browser

The search box covers four categories:

Category	Results shown	Limit	Icon
Blocks	Every matching block that has an item form	unlimited	Block item icon
Biomes	Matching biomes	5	Generated biome sprite
Structures	Matching structures	5	Structure icon
Entities	Matching entity types	unlimited	Spawn egg icon

Results are grouped under collapsible category headers with a match count. Matching is case-insensitive against both the registry ID and the display name; _, / and spaces count as word boundaries, multi-word queries require every word to match, and also one typo is tolerated for words of four or more characters (acient -> ancient). Click an entry to open its detail window. The detail window's own search field filters the displayed attributes; the compare window has a separate block search.

Biome Coverage

Versions	How it is computed
1.19+	Exact share of the vanilla multi-noise overworld climate preset.
1.14 – 1.18	World generation is layer-based, so the mod samples an independent copy of the overworld biome source across the whole world in the background. A measuring… percentage is shown until the result is ready.
Multiplayer	n/a — the client has no access to the server's biome source.

The result is specific to the current world seed.

Detail & Compare Windows

• Detail window — the full dump for one target, with an attribute search field, scrolling and line copying.
• Compare window — opened with Ctrl+C. It has its own block search list; pick a block to view a side-by-side attribute comparison against the selected target.

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Settings Menu

Options -> DevTools… opens the settings menu. The button is placed under the FOV slider, in the middle.

Button	Opens
HUD	Submenu for Colours and Preferences
Keybinds	Vanilla Key Bindings screen
Layout	Panel corner positioning and category ordering

Technical stuff

Configuration File (devtools.properties)

Location: .minecraft/config/devtools.properties

Key	Type	Purpose
tutorialSeen	true / false	Tutorial already shown / skipped forever
hud.color.<name>	8 hex digits AARRGGBB	HUD colour overrides (see table below)
pref.<key>	true / false	Per-line / per-section HUD preference
layout.position	TOP_LEFT, TOP_RIGHT, BOTTOM_LEFT, BOTTOM_RIGHT	Inspector panel corner
layout.categoryOrder	Comma-separated names	Custom More info category order

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HUD Colours Screen

Each line has a colour square, a hex code field, a copy button, and a reset button. Clicking the square opens a colour picker with Hue, Saturation, and Brightness sliders.

HUD Colour Keys (hud.color.*)

Config suffix	UI label	Role
bg	Background	Panel fill
borderTop	Border (top)	Top accent line
headerBg	Header background	Header band
header	Header label	“HOVERING” / “SELECTED” text
category	Category label	Section titles in dumps
key	Property key	Text before :
value	Property value	Text after :
dim	Dim text	Hints / secondary lines
scrollbar	Scrollbar track	Scroll gutter
scrollThumb	Scrollbar thumb	Scroll handle
boolTrue	True value	Boolean badge / styling
boolFalse	False value	Boolean badge / styling

(Note: Item rarity colours are strictly tied to vanilla and are not configurable here).

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HUD Preferences Screen

You can toggle exactly which lines show up. The top row, All Preferences, sets every other box on or off together.

General Preferences

Key	Label
pref.showIcon	Show icon
pref.showId	Show identifier

Block-related Preferences

Key	Label
pref.block.source	Source mod
pref.block.destroyTime	destroyTime
pref.block.resistance	resistance
pref.block.lightEmit	lightEmit
pref.block.lightDamp	lightDamp
pref.block.friction	friction
pref.block.speedFactor	speedFactor
pref.block.jumpFactor	jumpFactor
pref.block.isSolid	isSolid
pref.block.isAir	isAir
pref.block.liquid	liquid
pref.block.blocksMotion	blocksMotion
pref.block.canOcclude	canOcclude
pref.block.redstone	redstone
pref.block.randomTick	randomTick
pref.block.ignitedByLava	ignitedByLava
pref.block.stateProps	State properties
pref.block.blockEntity	Block entity NBT
pref.block.environment	Environment (biome/light)

Entity-related Preferences

Key	Label
pref.entity.source	Source mod
pref.entity.category	category
pref.entity.dimensions	dimensions
pref.entity.fireImmune	fireImmune
pref.entity.uuid	UUID
pref.entity.customName	customName
pref.entity.tags	tags
pref.entity.onGround	onGround
pref.entity.invulnerable	invulnerable
pref.entity.silent	silent
pref.entity.glowing	glowing
pref.entity.noGravity	noGravity
pref.entity.frozen	frozen
pref.entity.inWater	inWater
pref.entity.onFire	onFire
pref.entity.HP	HP
pref.entity.armor	armor
pref.entity.isBaby	isBaby
pref.entity.effects	Active effects
pref.entity.equipment	Equipment
pref.entity.noAI	noAI
pref.entity.persistent	persistent
pref.entity.leftHanded	leftHanded
pref.entity.target	target
pref.entity.owner	owner
pref.entity.rawNbt	Raw NBT

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Layout Screen

Control	Cycles through
Window position	Top Left -> Top Right -> Bottom Left -> Bottom Right
Ordering	Default, then “ First” for each known category.

Remember to press Save on the Colours, Preferences, and Layout screens to keep your changes.

Version differences

Older clients do not expose every data point. Instead of dropping lines, the mod shows a dim (unavailable on …) note:

Data point	First available
speedFactor, jumpFactor, suffocating, requiresTool per block	1.15+
Biome tags	1.16+
Datapack structure codec, jigsaw details, per-structure tags	1.16+ / 1.17+
Beehive block entity dump	1.15+
Ambient and music biome sounds	1.16+
Multi-noise climate parameters, raw biome JSON	1.16+
Biome fog, particles and colour overrides	1.15+
Exact biome coverage from the climate preset	1.19+

Data that exists only server-side (tick cost, block update history, per-chunk batch statistics) is shown as requires server debug, because a client-only mod cannot read it.

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License

DevTools is released under the MIT License.